The current plan is to mark off the areas that are not available for play, we're not happy with the current way the map is shown either. Adding a zoom is also something that's in the works, so we could use that as well, but the currently winning idea is to have the areas unavailable marked accordingly, something like this:

In 1440p, on 1080ti and 9700k I have mostly locked 144, with Smolensk and Polyarny dropping sometimes down to ~90fps, with some very rare drops to lower (firing closely at a wall, some level streaming drops etc).

Hello again! This week, we've got some much needed fixes, mainly for the missing packs. Let us know if indeed, everything is ok. There's a lot of other smaller, but also important fixes and it should improve the game overall. Thanks to everyone that helped test the update on the PTE. We strongly suggest installing the PTE, as there is potential for 60 player battles if we get enough of you. Remember, it can only happen on the PTE.
Update 0.8.2 Patch Notes
[OPTIMIZATION]
Asynchronous loading of replicated objects is now working properly (stuttering from loading other players should be reduced),
[BUGFIXES]
Fix for disappearing packs, and potentially for a lot of other replication issues,
Fixed HUDs changing during Kill Screen,
Fixed camera cliping while leaning against corner,
Partially fixed auto exposure in thermal scopes,
Fixed punishing after suicide,
Possible bugfix for invisble players,
Fixed laser not turning off properly,
Fixed pausing Reliable methods when replication is paused,
Disabled the ability to fire when interacting with objects using [Default: F],
Breakthrough: Fixed a bug with not ending retreat when retreat time ends,
Breakthrough: Fixed C2 spawn trap on Smolensk,
Fixed detonation timer sometimes not showing up properly on Breakthrough,
Fixed the map showing up on top of settings,
Fixed wrong vehicle spawned on Warsaw Warzone,
[IMPROVEMENTS]
Small improvements in the team manager code,
Breakthrough game code and replication improvements,
Clamped sharpen to 0-1 range instead of 0-3,
Added bCanAttachSemtexAndClaymore flag to mark vehicles to which semtex and claymore should not attach,
Reduced explosion camera shake for tank shells,
Breakthrough: Match timer will now pause during retreat,
Fixed other player stutters when coming into player view,
Gepard radars are no longer destructible,
Gepard Shells + spread improvement,
Improved vehicle LMG tracer visuals,
Fixed major D3D12 issues (DX12 is still not supported fully and will degrade performance, but some of you insist on running WW3 in DX12 and crashing),

I can't really remember, but I was under the impression that those were in the game since the start - but you can disable them. We've added those because we have 6 possible types of target you can hit and we wanted you to know what you're shooting (helmets, armor plates etc).

A small, but potentially very important update with a fix for those pesky disappearing packs. Turns out it was an engine error that could in theory break a lot of other things - so there's potentially a lot more fixes in this one than it looks like.
We've seen a few DX12 related crashes and we had those fixed internally already, so we decided to also include those fixes in this patch. This doesn't mean DX12 support! We just fixed a few bugs, DX12 is running much worse than DX11 version and it will stay like this for a long time!
Thanks for helping us test the game and make it better each update!
PTE 0.8.6 Patch Notes
[BUGFIXES]
Fix for disappearing packs, and potentially for a lot of other replication issues,
Fixed detonation timer sometimes not showing up properly on Breakthrough,
Fixed the map showing up on top of settings,
Fixed wrong vehicle spawned on Warsaw Warzone,
[IMPROVEMENTS]
Fixed major D3D12 issues (DX12 is still not supported fully and will degrade performance, but some of you insist on running WW3 in DX12 and crashing).

None of the questions you asked is really easy to answer right now, as we're currently focused on making the Linux servers working well and figuring out the infrastructure. Once we're closer to this feature being actively developed, we'll have more info, for now nothing is set in stone, so anything is possible.
Every version of implementing this feature has good and bad sides, for example, giving the community server executables means potentially easier time for hackers to reverse-engineer the game. It also means that we have to clearly show to people the difference between official and custom servers, so they don't get discouraged by finding only 'one weapon 999999 tickets warzone' or something.
On the other hand, making people that have the hardware buy a license is adding unnecessary steps for everyone and makes less possible servers.
It's a complicated issue that will be tackled most likely after the 1.0 full release.